Background and importance Ceftazidime–avibactam and ceftolozane–tazobactam are two second generation cephalosporin/β-lactamase inhibitor combinations. The antimicrobial spectrum of activity includes multidrug resistant gram negative bacteria, including Pseudomonas aeruginosa. Ceftazidime–avibactam is also active against carbapenem resistant Enterobacteriaceae that produce Klebsiella pneumoniae carbapenemases. Both drugs are approved for treatment of complicated intra-abdominal infections (cIAIs), complicated urinary tract infections (cUTIs), community acquired pneumonia (CAP) and ventilator associated bacterial pneumonia (VABP).

Aim and objectives To evaluate the use of ceftazidime–avibactam and ceftolozane–tazobactam in a Spanish general hospital (400 beds).

Material and methods A prospective descriptive study was carried out from October 2016 to September 2020 including all patients treated with ceftazidime–avibactam and ceftolozane–tazobactam at the hospital. Variables collected were demographic (age/sex) and clinical (type of infection, microorganism isolated, duration of treatment, dose administered, prescriber clinical service and antibiotic tested in the antibiogram).

Results 40 patients were included and the results are shown in table 1.

The most common dosage of ceftazidime–avibactam was 2 g every 8 hours. The prescribing clinical services were 33.3% general surgery (GS), 20.8% intensive care unit (ICU), 12.5% haematology, 8.3% oncology and 25.1% other. For ceftolozane–tazobactam, the most common dosage was 1 g every 8 hours, and the prescribing clinical services were 68.75% ICU, 12.5% internal medicine, 12.5% haematology and 6.25% GS.

Both antibiotics were susceptible in 75% of patients. Clinical and microbiological resolution of the infection was 75% for ceftazidime–avibactam and 70% for ceftolozane–tazobactam. 17.5% of patients died during hospitalisation because of their clinical situation.

Conclusion and relevance

• Both patient populations were demographically similar but the use of ceftazidime–avibactam was more frequent.

• cIAIs and pneumonias were the most common infections treated. Mostly, ceftazidime–avibactam was used for carbapenemase producing K pneumoniae and ceftolozane–tazobactam for P aeruginosa multiresistant.

• ICU and general surgery were the most experienced clinical services.

• Both antibiotics were tested in the antibiogram in most cases.

Conflict of interest No conflict of interest